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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <title>5.27</title>
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<body>
   
     <script>
     //字符串
     var str ='Hellow'

     //输出 1. length 字符串长度
     console.log(str.length('9'))

     //     2. charAt()  获取字符串指定位置的值
     console.log(str.charAt('6'))

     //     3.indexOf
     console.log(str.indexOf('1'))

     //4.lastcindexOf
     console.log(str.lastIndexOf('1'))

     //5. includes() 是否包含特定字符有匹配字符返回true否则false
     console.log(str.length('11'))

     //6.concat  用于字符串连接
     str1 = 'abc'
     str2 = '123'
     console.log(str.concat(str2))



</script>
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